feat(auth): migrate metrics/logging/monitoring tests from Mocha to Jest by vbudhram · Pull Request #20243 · mozilla/fxa

vbudhram · 2026-03-23T20:39:22Z

Because

The FxA auth-server is migrating from Mocha to Jest as part of FXA-12536
Metrics, logging, and monitoring test files in test/local/ used sinon/proxyquire/chai patterns that are being replaced with Jest-native equivalents
lib/monitoring.js had zero test coverage

This pull request

Migrates 7 Mocha test files to co-located Jest .spec.ts files in lib/
Adds 1 new test file for lib/monitoring.js (previously untested)
Uses Jest-native mocking (jest.fn(), jest.spyOn(), jest.mock()) instead of sinon
Replaces proxyquire with jest.resetModules() + jest.doMock() for modules with load-time side effects
Does not delete old Mocha files — deletion is a separate follow-up

Test migration summary

#	Old Test	New Spec	Tests	Assertions
1	`test/local/metricsCache.js`	`lib/metricsCache.spec.ts`	8	Identical
2	`test/local/sentry.js`	`lib/sentry.spec.ts`	10	Identical
3	(none — new test)	`lib/monitoring.spec.ts`	8	New coverage
4	`test/local/log.js`	`lib/log.spec.ts`	28	Identical
5	`test/local/metrics/context.js`	`lib/metrics/context.spec.ts`	39	Identical
6	`test/local/metrics/amplitude.js`	`lib/metrics/amplitude.spec.ts`	475*	Identical
7	`test/local/metrics/events.js`	`lib/metrics/events.spec.ts`	33*	Identical
8	`test/local/metrics/glean.ts`	`lib/metrics/glean/index.spec.ts`	53	Identical
	Total		654	No gaps

Issue

Closes: https://mozilla-hub.atlassian.net/browse/FXA-12562

Checklist

My commit is GPG signed
Tests pass locally (if applicable)
Documentation updated (if applicable)
RTL rendering verified (if UI changed)

Other Information

Verification:

cd packages/fxa-auth-server
npx jest --testPathPattern="(metricsCache|lib/sentry|monitoring|lib/log|metrics/context|metrics/amplitude|metrics/events|metrics/glean/index)\.spec" --no-coverage
# Result: 8 suites, 654 tests, 0 failures

Key decisions:

jest.mock('@sentry/node') used for sentry.spec.ts because Sentry exports are frozen/non-configurable — jest.spyOn cannot redefine them
monitoring.spec.ts extracts filterSentryEvent from initMonitoring call args since it's not exported
events.spec.ts uses sinon .callCount/.args for metricsContext methods since mocks.mockMetricsContext() returns sinon spies
M6 adds .catch(() => {}) on an intentionally-rejected promise to avoid Node 22 unhandled rejection crashes

Copilot

Pull request overview

This PR advances the FxA auth-server’s migration from Mocha to Jest by moving metrics/logging/monitoring tests into co-located lib/**/*.spec.ts suites (and adding new coverage for previously-untested monitoring initialization behavior).

Changes:

Migrates Mocha test/local/** suites to Jest lib/**/*.spec.ts, replacing sinon/proxyquire/chai patterns with Jest-native mocking.
Adds a new Jest suite for lib/monitoring.js to cover its module-load initMonitoring() behavior and Sentry event filtering.
Introduces Jest coverage for supporting modules like Sentry config, metrics cache, and metrics event emitters.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
packages/fxa-auth-server/lib/sentry.spec.ts	Jest migration of Sentry-related tests and helper coverage.
packages/fxa-auth-server/lib/monitoring.spec.ts	New Jest coverage for `lib/monitoring.js` module-load monitoring init and filter behavior.
packages/fxa-auth-server/lib/metricsCache.spec.ts	Jest migration for `MetricsRedis` cache behavior with Redis/TypeDI isolated via mocks.
packages/fxa-auth-server/lib/metrics/glean/index.spec.ts	Jest migration for Glean server-side event metrics and error logging behavior.
packages/fxa-auth-server/lib/metrics/events.spec.ts	Jest migration for metrics event emission behavior (activity/flow/route flow events).
packages/fxa-auth-server/lib/metrics/context.spec.ts	Jest migration for metrics context stash/get/gather/propagate/validate behaviors.
packages/fxa-auth-server/lib/metrics/amplitude.spec.ts	Jest migration for Amplitude event mapping/validation tests (with TypeDI involvement).
packages/fxa-auth-server/lib/log.spec.ts	Jest migration for logger initialization, amplitude validation handling, and notifications.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2026-03-24T13:36:55Z

packages/fxa-auth-server/lib/sentry.spec.ts

+  it('can be set up when sentry is not enabled', async () => {
+    let throws = false;
+    try {
+      await configureSentry(server, config);
+    } catch (err) {
+      throws = true;
+    }
+    expect(throws).toBe(false);
+  });


The test "can be set up when sentry is not enabled" doesn’t actually disable Sentry: beforeEach always sets config.sentry.dsn to a non-empty value, so this test exercises the same enabled branch as the prior test. Set config.sentry.dsn to a falsy value for this test (or avoid setting it unconditionally in beforeEach) so the no-DSN path is covered.

Copilot · 2026-03-24T13:36:56Z

packages/fxa-auth-server/lib/metrics/amplitude.spec.ts

+Container.set(StatsD, { increment: jest.fn() });
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+const mocks = require('../../test/mocks');
+const { version } = require('../../package.json');
+
+const amplitudeModule = require('./amplitude');
+
+const mockAmplitudeConfig = {
+  schemaValidation: true,
+  rawEvents: false,
+};
+
+const DAY = 1000 * 60 * 60 * 24;
+const WEEK = DAY * 7;
+const MONTH = DAY * 28;
+
+// ---------------------------------------------------------------------------
+// Tests
+//
+// NOTE: mocks.mockLog() returns sinon spies, so we access call data via the
+// sinon API (.callCount, .args) rather than the jest mock API (.mock.calls).
+// StatsD instances created with jest.fn() use the jest API.
+// ---------------------------------------------------------------------------
+
+describe('metrics/amplitude', () => {
+  afterEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  afterAll(() => {
+    Container.reset();
+  });


This spec mutates the global TypeDI Container at module load (Container.set(StatsD, ...)) and only calls Container.reset() in afterAll. That can leak DI state into other Jest suites running in the same worker and make results order-dependent. Please move the Container.set into a beforeEach and call Container.reset() in afterEach (this is the pattern used in other specs, e.g. lib/account-events.spec.ts:56-58, lib/account-delete.spec.ts:156-159).

I added this

…st (FXA-12562)

vbudhram · 2026-03-24T13:58:14Z

@nshirley I've also addressed feedback from copilot and reviewed this code (verified parity on assertions, tests and coverage). The biggest change was the added coverage to lib/monitoring.js, not sure but original ticket called out adding it but there was no tests for it. It was straightforward to add so I did.

Welcome to give this a pass over as well.

nshirley

Thanks for adding the new tests for monitoring!

vbudhram force-pushed the fxa-12562 branch from 13b4b64 to 61cf428 Compare March 24, 2026 02:59

vbudhram self-assigned this Mar 24, 2026

vbudhram marked this pull request as ready for review March 24, 2026 13:31

vbudhram requested a review from a team as a code owner March 24, 2026 13:31

Copilot AI review requested due to automatic review settings March 24, 2026 13:31

Copilot started reviewing on behalf of vbudhram March 24, 2026 13:32 View session

Copilot AI reviewed Mar 24, 2026

View reviewed changes

vbudhram force-pushed the fxa-12562 branch from 61cf428 to e334e75 Compare March 24, 2026 13:48

feat(auth): migrate metrics/logging/monitoring tests from Mocha to Je…

524bce3

…st (FXA-12562)

vbudhram force-pushed the fxa-12562 branch from e334e75 to 524bce3 Compare March 24, 2026 13:49

nshirley approved these changes Mar 24, 2026

View reviewed changes

vbudhram merged commit cf94c97 into main Mar 24, 2026
21 checks passed

vbudhram deleted the fxa-12562 branch March 24, 2026 18:12

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

feat(auth): migrate metrics/logging/monitoring tests from Mocha to Jest#20243

feat(auth): migrate metrics/logging/monitoring tests from Mocha to Jest#20243
vbudhram merged 1 commit intomainfrom
fxa-12562

vbudhram commented Mar 23, 2026 •

edited

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Mar 24, 2026

Uh oh!

Copilot AI Mar 24, 2026

Uh oh!

vbudhram Mar 24, 2026

Uh oh!

vbudhram commented Mar 24, 2026

Uh oh!

nshirley left a comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

vbudhram commented Mar 23, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Because

This pull request

Test migration summary

Issue

Checklist

Other Information

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI Mar 24, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 24, 2026

Choose a reason for hiding this comment

Uh oh!

vbudhram Mar 24, 2026

Choose a reason for hiding this comment

Uh oh!

vbudhram commented Mar 24, 2026

Uh oh!

nshirley left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

vbudhram commented Mar 23, 2026 •

edited

Loading